Modular structural surface assembly

ABSTRACT

A modular surface assembly includes a plurality of panels, each panel having a planar top surface, a double-wall skirt extending around the perimeter of the planar surface and defining a narrow gap between the two walls of the skirt. Collinear first holes extend through the skirt at a first location along the skirt and collinear second holes extend through the skirt at a second location along the skirt spaced from the first location. A first connector extends through the first holes and into the gap of one panel for connecting the one panel to an adjacent similar panel at the first location, and a second connector extends through the second holes and into the gap of the one panel for connecting that panel to the adjacent panel at the second location. Various connector designs are also disclosed.

[0001] This invention relates to a modular structural surface assembly. It relates more particularly to a panel construction and connectors therefor which enable a multiplicity of such panels to be connected together in various configurations to provide walkways, bicycle paths, beach access, flooring, shelving, benches, vehicle barriers, shipping containers and other similar surfaces and structures.

BACKGROUND OF THE INVENTION

[0002] Modular structural surfaces of the type with which we are concerned here can be used in a wide variety of applications such as to define bicycle paths, pedestrian paths, nature trails, beach access, as well as large area flooring for tents, outdoor events, etc. While we will describe the invention, primarily in terms of a flooring system, it should be understood that it has equal application to form structures such as paths, walkways, helicopter landing pads, benches, barriers, containers shelving and the like. Usually such modular flooring surfaces with structural load carrying capacity are formed by an assembly of panels or modules which are connected together to provide the required surface is area. These panels are often formed as wood pallets, plywood and lumber frameworks, metal gratings and the like which are prone to damage and deterioration, quite heavy, bulky, and difficult to move around for assembly, particularly in rough terrain. Also, the limited number of flooring panels in use are difficult to assemble because the connectors used to connect the various panels comprise threaded fasteners, hook and eye connectors, and the like which may protrude from the panels where they can be readily broken or are hard to install and often require the use of special installation tools.

[0003] Many prior structural flooring systems are also disadvantaged in that they do not conform well to the contours of the surface on which they are placed primarily because of the rigidity of the connections between the modules which make up the flooring system. As a result, the modules have to be rigid enough and the connections have to be strong enough to bridge depressions in the supporting surface, which increases the required weight, thickness and the overall cost of the flooring system.

SUMMARY OF THE INVENTION

[0004] Accordingly, it is an object of the present invention to provide an improved modular surface assembly for lending finished surfaces to bicycle paths, walkways, floor areas and the like.

[0005] Another object is to provide an assembly such as this which is composed of individual panels which can be assembled and disassembled relatively easily without any special tools.

[0006] Another object of the invention is to provide a modular surface assembly which can follow the general contours of the underlying ground or manmade surface on which it is placed while providing a firm, dry, uniform surface for the user.

[0007] A further object of this invention is to provide a modular surface assembly composed of similar panels which can be arranged in a variety of different configurations to cover a selected surface area.

[0008] Another object of the invention is to provide a panel for a modular surface assembly which can be connected easily to similar panels to form a finished surface having practically any desired geometry and size.

[0009] An additional object of the invention is to provide a modular surface assembly system that can be shipped and stored compactly with no protruding parts that can snag or break.

[0010] Yet another object of the invention is to provide improved connection means for connecting adjacent panels of a modular surface assembly.

[0011] A further object of the invention is to provide a slightly elevated surface that when placed over impermeable underlying surfaces such as asphalt or concrete allows water to drain and flow underneath.

[0012] An additional object of the invention is to provide a slightly elevated, resilient surface that when placed over hard underlying surfaces such as asphalt or concrete provides cushioning and anti-fatigue benefits to people standing on the surface.

[0013] Other objects will, in part, be obvious and will, in part, appear hereinafter.

[0014] The invention accordingly comprises the features of construction, combination of elements and arrangements of parts which will be exemplified in the following detailed description, and the scope of the invention will be indicated in the claims.

[0015] Briefly, the modular surface assembly incorporating this invention comprises a plurality of similar panels and means for rigidly or flexibly connecting together adjacent panels in a selected layout to form a finished surface having the desired geometry and surface area. As will be seen, the panels can be connected together in different ways to form a straightaway, a corner, a tee or a block to suite a particular application. As such, the assembly can be placed on an indoor or outdoor support surface or on the ground to form a variety of different finished surfaces, e.g., a bicycle, pedestrian or wheelchair access path, a nature trail, a beach access, a light vehicle path, a roof walkway, trade show booth floor, tent flooring, or dock surface, etc.

[0016] As will be described in more detail later, each panel comprises a preferably planar top surface having a depending double-wall skirt extending around the periphery of the underside of the planar top surface. In other words, each skirt is formed by a pair of closely spaced-apart parallel walls which extend all around the panel. Additional double-wall rib structures may extend across the panel at spaced-apart locations along the panel. Preferably, these rib structures are spaced from the ends of the panel and from each other a distance substantially equal to the panel width or an integral sub-multiple thereof.

[0017] Collinear first holes extend through the skirt at a first location along the skirt and collinear second holes extend through the skirt at a second location along the skirt spaced from the first location. A first connector extends through the first holes and into the gap of one panel for connecting the one panel to an adjacent similar panel at the first location and a second connector extends through the second holes and into the gap of the one panel for connecting that panel to the adjacent panel at the second location. Each connector is similarly connected to the adjacent panel. As will be described, various different types of connectors may be used to connect adjacent panels depending upon the particular application.

[0018] As will also be seen, the panels may be assembled to provide a finished surface of almost any shape and size and the assembly allows the panels to flex relatively so that the assembly can follow the contour of the surface on which it is placed yet provide a firm, dry, uniform surface for the user.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] For a fuller understanding of the nature and objects of the invention, reference should be made to the following detailed description taken in connection with the accompanying drawings, in which:

[0020]FIG. 1 is perspective view from above showing a plurality of panels connected together to form a surface assembly according to the invention;

[0021]FIG. 2 is a perspective view from below, on a larger scale, of one of the panels in FIG. 1;

[0022]FIG. 2A is fragmentary sectional view on a still larger scale of a portion of the FIG. 2 panel;

[0023]FIG. 3 is a perspective view on a much larger scale showing a connector for connecting together the panels of the assembly depicted in FIG. 1;

[0024]FIG. 4A is a fragmentary elevational view with parts broken away showing a pair of panels connected together using the FIG. 3 connector;

[0025]FIG. 4B is a sectional view with parts broken away taken along the line 4B-4B of FIG. 4A;

[0026]FIG. 5 is a perspective view of another connector embodiment;

[0027]FIG. 6 is a fragmentary perspective view with parts cut away showing a self aligning connector embodiment;

[0028]FIG. 7 is a fragmentary bottom plan view with parts broken away showing the interior connection of four panels, using a combination of the connector bracket shown in FIG. 3 and the double ended connector shown in FIG. 5;

[0029]FIG. 8 is similar view showing the interior connection of four panels using a different combination of the FIGS. 3 and 5 connectors;

[0030]FIG. 9 is a fragmentary sectional view of a panel retention bracket which may be part of the FIG. 1 assembly;

[0031]FIG. 10 is a perspective view of a tool which may be used to facilitate assembly and disassembly of the panels in FIG. 1;

[0032]FIG. 11 is a plan view of a surface assembly laid out to illustrate various possible assembly configurations and panel connections;

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Referring to FIG. 1 of the drawings, the present modular surface assembly comprises a plurality of generally rectangular panels shown generally at 10 connected together edge to edge in a manner to be described. Each panel 10 comprises a usually planar top surface 11 provided with an array of small drainage holes 12 arranged in columns and rows over the area of top surface 11. Also formed in the top surface 11 is an array of small arcuate treads 13 each tread being adjacent to a hole 12 to provide the top surface 11 with an upper traction surface. Extending down from the top surface 11 is a pair of opposite side walls 14, 14 and a pair of opposite end walls 16, 16. For reasons to be described later, a pair of small holes 32 is formed in each of the side walls 14 adjacent to the opposite ends thereof. A similar pair of holes 34 is provided in each end wall 16 adjacent to the opposite ends thereof. Preferably, each panel 10 has a length (X) which is an integral multiple of the panel width (Y).

[0034] Referring to FIGS. 2 and 2A which show the underside of a panel 10, an inner side wall 14 a is spaced parallel to each side wall 14. Likewise an inner end wall 16 a is spaced parallel to each end wall 16 so that panel 10 actually has a double-wall peripheral skirt structure 35 with a gap G between its walls. Structure 35 not only helps to rigidify panel 10, but it is also used to connect together adjacent panels 10 in a matter to be described. The inner side walls 14 a are provided with holes 32 a aligned with holes 32 in the side walls 14. Likewise, holes 34 a are present in the inner end walls 16 a, those holes being aligned with the holes 34 in the end walls 16.

[0035] As shown in FIG. 2, double-wall transverse rib structures 36, each having a gap G, extend between inner side walls 14 a at spaced-apart locations along panel 10. Preferably, structures 36 are spaced from inner end walls 16 a and from each other a distance substantially equal to an integral sub-multiple of the panel width (Y). For a typical panel 10 that measures two feet by four feet, the rib structures 36 may be spaced one foot apart along the panel. Through holes 30 are present adjacent to the opposite ends of rib structures 36. As will be described later, these double-wall rib structures 36 are used to connect together adjacent panels 10 to form a corner or a tee.

[0036] Interleaved with rib structures 36 is a plurality of single-wall transverse ribs 37 and additional dependent ribs 38 extend longitudinally between rib structures 36 and ribs 37 and between those ribs 37 and inner end walls 16 a at spaced apart locations across panel 10. Still more ribs 39 extend transversely between adjacent ribs 38 and between those ribs and the inner side walls 14 a. All of the aforesaid double-wall structures and ribs combine to make panel 10 a very strong, rigid yet light weight structure. Preferably, each panel 10 is molded as a unitary part of a strong, weather-resistant, impact-resistant, rot proof, UV resistant material such as high density polyethylene or a polycarbonate.

[0037] In some applications, it may be desirable to stiffen the panels even more. This may be done by press fitting stiffening strips S, e.g. of fiberglass, into the gaps G of the various skirt and/or rib structures 35, 36 as shown in FIGS. 2 and 2A.

[0038] Refer now to FIG. 3 which shows generally at 40, a connector used to connect together the adjacent panels 10 in FIG. 1. Connector 40 comprises a bracket 41 having a generally rectangularly bottom wall 42 and a pair of tabs 44 a and 44 b extending up from a side edge of wall 42 at spaced apart locations therealong. In other words, there is a space or gap 46 between tabs 44 a and 44 b which gap is wider than twice the width of the skirt structure 35 extending around panel 10, i.e. the distance between the outer surface of the outer panel wall 14 or 16 and the inner surface of the inner panel wall 14 a or 16 a. Also, the thickness of tabs 44 a and 44 b is slightly less than the width of the gaps G in skirt structure 35 and rib structures 36. Preferably, bracket 41 is made of a suitable, strong, rigid material such as aluminum pultruded fiberglass or super tough plastic.

[0039] As seen in FIG. 3, a hole 48 a extends through tab 44 a and a similar hole 48 b extends through tab 44 b, each of these holes being adapted to receive a locking pin 52, one end of which is fitted with a ring 54. Preferably, a small boss or spring-loaded ball detent 53 is provided adjacent the opposite tapered end of 52 a of each pin 52 to provide a tight fit as the pin 52 is passed through the tab hole 48 a or 48 b so that once the pin is inserted through its hole, it takes appreciable force or effort to withdraw the pin from that hole. A typical pin 52 may be about ⅜ inch in diameter and 1½ inches long and be made of a suitable rigid material such as aluminum or stainless steel.

[0040] Referring now to FIGS. 4A and 4B, in order to connect adjacent panels 10 together, e.g. end to end, a pair of the FIG. 2 connectors 40 may be used, one at each side of the panel assembly as shown in FIGS. 1 and 11. With the locking pins 52 removed, the connector bracket 41 is inserted under the corners of the abutting panels so that the tab 44 a extends into the gap G between the side walls 14, 14 a, of one panel and the tab 44 b is inserted into the gap G between the corresponding side walls 14, 14 a of the adjacent panel 10. Preferably, the bracket is oriented so that the bracket bottom wall 42 extends under the panels as shown in FIG. 4B so that it is out of the way. As noted above, the space 46 between tabs 44 a and 44 b is wide enough to receive the inner and outer end walls 16, 16 a of both panels. When each bracket 41 is properly positioned under the panels as shown, the tab holes 48 a and 48 b are aligned with the holes 32 and 32 a adjacent the corresponding corners of the abutting panels 10. With each bracket and the panels in proper alignment, pins 52 can be inserted, in turn, through the holes 32, 48 a and 32 a thereby releasably securing each bracket 41 to both panels. The ring 54 at the head of each pin limits pin penetration into the panels. With both connectors 40 in place as shown in FIG. 1, the two panels 10 are firmly secured together. A similar procedure may be employed to connect panels 10 side to side.

[0041] Preferably, the holes 48 a and 48 b in each bracket 41 are spaced above the bracket bottom wall 42 so that there is some clearance between the bracket bottom wall 42 and the bottom edges of the panel skirt structure 35 as well as clearance between the tops of the bracket tabs and the undersides of the panel support surfaces. This allows some pivoting motion of the panels relative to connectors 40, so that when the panels are laid on an uneven surface, the panel assembly can adjust somewhat to the contour of that surface.

[0042] Also, if stiffening inserts S are present in the gaps G between the panel end walls 16 and 16 a as shown in FIG. 2A, the bottom wall 42 of each bracket 41 extends under the ends of those inserts and helps to hold the inserts in place.

[0043] Using connectors 40, a multiplicity of panels 10 can be connected together end to end or side to side as shown in the upper portion of FIG. 11. These connections can be made in a minimum amount of time to form a pathway, flooring or the like. Furthermore, this can be done without requiring any tools whatsoever. When the time comes to disassemble the pathway or flooring, that can be done simply by pulling out the various locking pins 52 from the corresponding brackets 41 which allows the panels 10 to be separated and stacked for transport or storage.

[0044] It is evident from FIG. 11 that the panels 10 can be connected to form straight pathways, inside and outside corners, tees as well as large surface areas depending upon the particular application. To form a corner or a tee, the double-wall rib structures 36 are utilized in the same way as the double-wall skirt structure 35. For example, in FIG. 11, the lower end of the third panel 10 down is centered on the side of the next panel 10 so that the side walls 14, 14 a of the former panel are aligned with the double-wall structure 36 of the latter panel. This allows the bracket tabs 44 a and 44 b to be plugged into the gaps G between those side walls 14, 14 a and into the structure 36 of the lower panel so that the bracket holes 44 a and 44 b are aligned with the holes 32, 32 a of the upper panel and hole 30 of the lower panel, respectively. Once the pins 52 are inserted through those holes, the two panels are securely connected together to form a tee. A corner may be formed in more or less the same way by joining the end of one panel to the side of an adjacent panel with a connector 40 being present at the middle double-wall structure 36 of the latter panel as shown at the left side of FIG. 11.

[0045] Refer now to FIG. 5 which shows generally at 60 a different type of connector for connecting together adjacent panels 10. Connector 60 is more or less a double-ended version of pin 52 depicted in FIG. 2. In other words, connector 60 comprises a pair of mirror-image pin sections 62 a and 62 b connected back-to-back, there being a flange 64 at the boundary between the two sections. Pin section 62 a has a tapered end 62 aa and pin section 62 b has a tapered end 62 bb. As with pin 52, small bosses or bumps 65 may be provided near those ends to help hold the pin sections in place when connecting adjacent panels 10. Alternatively, in lieu of bosses 65, connector may be formed with slightly bulbed ends as shown in phantom in FIG. 5 so that they will pass through the panel and bracket holes with a tight fit and thus hold better once they are fully pressed into place. Typically, connector 60 is about 3 inches long and has a diameter in the order of ⅜ inch so that it can fit snugly into the holes 32, 32 a and 34, 34 a in panels 10.

[0046] To connect together adjacent panels 10 using connectors 60 by themselves, one end of each connector is inserted into the holes 32, 32 a or 34, 34 a of one panel 10 and the opposite end of that connector is inserted into the holes 32, 32 a or 34, 34 a of the adjacent panel 10 and the two panels are pushed together. The flange 64 in the middle of connector 60 functions as a stop to prevent over insertion of the connector into any one panel. When the panels are being placed on a relatively smooth surface, the connectors 60 can be of a relatively rigid material, such as aluminum or stainless steel. On the other hand, when the panels are to be positioned on a contoured surface, it may be preferable to use connectors which are slightly flexible, e.g. of nylon, so that the adjacent panels can move up and down or flex relative to one another.

[0047] When connecting together adjacent panels 10 at their corners, the procedure is facilitated by using the self aligning connection shown generally at 40′ in FIG. 6. Connector 40′ comprises a bracket 41 which is similar to bracket 41 (FIGS. 4A and 4B) except that the inside corners 45 a and 45 b of its tabs 44 a′ and 44 b′ are beveled or cut on a bias at an angle of about 45°. Accordingly, when the bracket 41 is inserted into the gaps G of two adjacent panels 10 at the corners of the panels as shown in FIG. 6, the tapered edges 45 a, 45 b of the brackets guide the panels into the proper positions.

[0048] Preferably, the space between tabs 44 a′ and 44 b′ is sized to just accommodate the combined widths of the skirt structures 35 of the two panels so that the holes 48 a′ in the tabs come very close to lining up with the panel holes 32, 32 a or 34, 34 a (FIG. 1) when the bracket is seated in the panels. The bracket 41′ may be releasably retained in the panels by either pins 52 as shown or by double ended connectors 60 or by one of each, depending on the circumstances. It should be noted that the self aligning connector brackets 40′ are short enough to be packed for convenient shipment in the pockets formed by the higher ribs on the undersides of the panels.

[0049] When panels 10 are to be assembled on relatively rough terrain so that forces may be developed tending to pull the panels apart, it may be desirable to use a combination of connector 60 and bracket 41 depicted in FIG. 2, or bracket 41′ shown in FIG. 6 with the connector 60 replacing the locking pins 52 in the bracket. FIG. 7 illustrates generally at 70 an interior connection of four panels 10 using a single bracket 41 and a pair of connectors 60. This type of connection is useful when stiffening inserts S (FIG. 2) are not used. As seen from FIG. 7, the bracket tabs 44 a and 44 b are inserted into the gaps G at the corners at the upper pair of panels 10. The sections 62 a of a pair of connectors 60 are inserted through the holes 32, 32 a or 34, 34 a of the upper pair of panels and then the other sections 62 b of those connectors are inserted through the corresponding holes in the lower pair of panels, with the bracket bottom wall 42 extending under one pair of panels. While firmly holding all four panels together, this connection 70 still allows relative flexing of those panels so that the overall assembly can follow the contour of the terrain which it covers.

[0050]FIG. 8 shows generally at 80 an interior connection for connecting four panels 10 fitted with fiberglass stiffening elements S in gaps G. This arrangement is desirable if the assembly extends over rough ground and will be subjected to heavy loading. As seen from that figure, connection 80 utilizes two brackets 41 (or 41′) and two double-ended connectors 60 to hold the brackets in place. The panels are assembled in the same way as described above in connection with FIG. 7. Here however, the bottom walls 42 of the two brackets 41 extend under the upper and lower pairs of panels, respectively, and help to hold the stiffening inserts S in place within their respective gaps G. As with connection 70, connection 80 allows some relative flexing motion of the adjacent panels 10.

[0051] In large flooring installations there may be a need to positively prevent adjacent panels from pulling apart in the interior portions of an installation. In this event, the joint between adjacent panels 10 may include a retention bracket 90 shown generally in FIG. 9.

[0052] Bracket 90 comprises an elongated generally L-shaped member having a horizontal base 92 and a vertical leg 94 which is adapted to fit in the edge gap G of a panel 10 (or behind the skirt 35 of that panel) such that base 92 extends laterally from that panel. Bracket 90 also includes an upwardly angled wall or leg 96 extending from the edge of base 92 remote from leg 94. The bracket is dimensioned such that the upper end 96 a of leg 96 is spaced from leg 94 a distance somewhat greater than the total thickness of the peripheral skirt structure 35 of panel 10. This allows a second panel 10 to be positioned on bracket 90 next to the first panel 10 so that its skirt structure 35 drops down into the gap between leg 94 and the leg end 96 a as shown in FIG. 8, thereby locking together the adjacent panels 10, 10. In some applications, the angled leg 96 may be substituted for by a vertical leg 96′ engaged in the gap G of the second panel 10 as shown in phantom in FIG. 9. Also if desired, collinear holes 97 a and 97 b may be provided in legs 94 and 96, respectively, to accept a pin 52 (FIG. 3) for locking the bracket to the panels.

[0053] Bracket 90 may be of metal or more preferably of extruded plastic cut to a suitable length. Preferably, leg 94 of bracket 90 is thin enough so that it does not bind when inserted into panel gap G. This will allow the bracket to drop away from and unlatch the panels 10, 10 when the panels are lifted slightly during disassembly of the surface assembly.

[0054] As mentioned above, my modular surface assembly may also be used to form walls, containers and the like. This requires that panels 10 be connected at right angles to one another. For this, the drainage holes 12 in the panels may be formed with the same diameter as the pin-receiving holes 32, 34 in the panel skirt 35. This allows one panel 10 to be positioned edge-wise on top of a second panel 10 such that the skirt holes 32 or 34 of the former are aligned with the drainage holes 13 of the latter. The two panels may then be joined by locking pins 52 or connectors 60 through the aligned holes of the two panels.

[0055] As noted above, the panels 10 of my modular surface assembly may be connected and disconnected without tools. However, that process may be facilitated using the tool 100 illustrated in FIG. 10. Tool 100 comprises an elongated spike-like body 102 having a tapered end 102 a and a head 102 b to which is welded a washer or ring 104. Body 102 has a slightly smaller diameter than the holes 30, 32, 34 (FIG. 1) in panels 10.

[0056] When assembling adjacent panels 10, the panels (and any intervening bracket 41, 41′) may be positioned so that their corresponding pin holes are aligned sufficiently to receive the pointed end 102 a of tool 100. Then, by wiggling the tool back and forth, the s5 holes can be brought into fine alignment so that the locking pins 52 or connectors 60, can be slid into place without the need to look at or position a panel 10 or bracket 41, 41 ′by trial and error.

[0057] The heavier head end 102 b of tool 100 may be used to tap a pin or connector into place if the fit is tight and the washer 104 may be used to remove a double-ended connector 60 (FIG. 5) from a panel 10. For this, the washer 104 may be slipped over the exposed end of connector 60 and then moved out of alignment with same causing the inner edge 104 a of the washer to grip opposite sides of the connector. Then, when the tool 100 is moved away from the panel, the tool will extract the pin from the panel.

[0058]FIG. 11 illustrates a surface assembly comprising a multiplicity of panels 10 in a variety of orientations connected by the different panel connections already described to form inside and outside corners, tees, blocks, straightaways, etc. Panels 10 can be assembled in this way to cover an area of almost any shape and size. Being composed of relatively small thin panels, the overall assembly can be laid down and dismantled in a relatively short time and stored in a minimum amount of space until needed.

[0059] It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained. Also, certain changes may be made in the above construction without departing from the scope of the invention. For example, for the connection 80, two of the brackets 41 or 41′ may be formed as a unitary part, i.e. with the tabs extending along the centerline of the bottom wall. Also, the panels may have shapes other than a rectangle, e.g. square, trapezoid, parallelogram, polygon. Therefore, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

[0060] It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention described herein. 

What is claimed is:
 1. A modular surface assembly comprising: a panel including a support surface, a double-wall skirt extending around the perimeter of the support surface and defining a narrow gap between the two walls of the skirt, collinear first holes extending through the skirt at a first location along the skirt, collinear second holes extending through the skirt at a second location along the skirt spaced from the first location; a first connector for extending through said first holes and into said gap for connecting said panel to an adjacent similar panel at said first location, and a second connector for extending through said second holes and into said gap for connecting said panel to the adjacent similar panel at said second location.
 2. The assembly defined in claim 1 and further including drainage holes in said support surface said drainage holes having substantially the same diameter as the collinear holes in the skirt so that said connected-together panels may be perpendicular to one another.
 3. The assembly defined in claim 1 and further including additional collinear holes along said skirt for receiving additional connectors.
 4. The assembly defined in claim 1 wherein said panel is rectangular with a length which is an integral multiple of the panel width, said skirt including side segments which extend along the sides of the panel and end segments which extend along the ends of the panel.
 5. The assembly defined in claim 4 wherein the panel also includes at least one double-wall linear rib structure extending from the underside of the support surface between said skirt side segments, said rib structure defining a narrow gap between the two walls of the rib structure, said rib structure being spaced along the panel from one of said skirt end segments by a distance corresponding substantially to the panel width or one-half the panel width.
 6. The assembly defined in claim 5 and further including additional ribbing extending from the underside of the support surface and extending between said skirt end segments and said rib structure so as to stiffen the panel.
 7. The assembly defined in claim 5 and further including additional collinear holes extending through the double-wall rib structure.
 8. The assembly defined in claim 1 wherein the first connector comprises: a bracket having a bottom wall; a pair of coplanar tabs extending up from the bottom wall at spaced-apart locations therealong; means defining a hole extending through each tab, the thickness of said tabs being slightly smaller than the width of said skirt gap so that said bracket can be engaged under the panel with one of said tabs extending into the gap between the two walls of the skirt to place the hole therein tab in alignment with the first collinear holes in said skirt, and a pin insertable into said aligned holes in the skirt and tab so as to lock the bracket to the panel.
 9. The assembly defined in claim 8 wherein said pin is appreciably longer than the total thickness of said double-wall skirt.
 10. The assembly defined in claim 8 wherein, the panel is generally rectangular with four corners and the first and second collinear holes are located near adjacent corners of the panel; the space between said bracket tabs is wider than twice the total thickness of said double-wall skirt, and the bracket is engaged under the panel so that the hole in one of said tabs is aligned with the first collinear holes in said panel and the other tab extends up from the bracket bottom wall outside the panel skirt in order to engage an adjacent similar panel.
 11. The assembly defined in claim 8 wherein said pin comprises a double-ended pin composed of coaxial mirror-image pin sections having first ends connected together and tapered second ends, each pin section being longer than the total thickness of said double-wall skirt.
 12. The assembly defined in claim 8 wherein the tabs have opposing corners which are beveled.
 13. The assembly defined in claim 1 wherein said connector comprises a double-ended pin composed of coaxial mirror image pin sections having first ends connected together and second ends, each pin section being longer than the total thickness of said double-wall skirt.
 14. The assembly defined in claim 13 wherein said connector is somewhat flexible.
 15. The assembly defined in claim 1 wherein the second ends of the connector are tapered.
 16. The assembly defined in claim 1 wherein the second ends of the connector are enlarged.
 17. The assembly defined in claim 1 and further including an elongated stiffening member extending along the gap in said double-wall skirt.
 18. The assembly defined in claim 1 and further including a panel retention bracket connecting said panels, said retention bracket having a base, with two legs extending from the base and spaced apart by a distance no greater than about twice the thickness of said skirt and no less than about twice the thickness of a wall of said skirt.
 19. The assembly defined in claim 18 and further including collinear pin-receiving holes in said retention bracket legs.
 20. The panel defined in claim 10 wherein said bracket tabs and the holes therein are dimensioned and arranged so that when the hole in said one tab is aligned with the first collinear holes in said skirt and said pin is inserted into said holes in the skirt and one tab, the one tab is spaced from the underside of the top surface and the skirt is spaced from the bottom wall of the bracket, so that the bracket and panel can pivot relatively about the pin.
 21. A panel for a modular surface assembly comprising: a support surface; a double-wall skirt extending around the perimeter of the top wall and defining a narrow gap between the two walls of the skirt; collinear first holes extending through the skirt at a first location along the skirt, and collinear second holes extending through the skirt at a second location along the skirt spaced from the first location.
 22. The panel defined in claim 21 wherein the panel is rectangular with a length which is an integral multiple of the panel width, said skirt including side segments which extend along the sides of the support surface and end segments which extend the along the ends of the support surface.
 23. The panel defined in claim 22 and further including at least one double wall rib structure extending from the underside said support surface between said skirt side wall segments, said rib structure defining a narrow gap between the two walls of said rib structure, said rib structure being spaced along the underside of the support surface from one of said skirt end segments by a distance substantially corresponding to the panel width or one-half the panel width.
 24. The panel defined in claim 23 and further including additional collinear holes extending through the double-wall rib structure adjacent to the ends of the rib structure.
 25. A connector for a modular surface assembly composed of a plurality of panels, a said connector including: a bracket having a bottom wall and a pair of coplanar tabs extending up from the bottom wall at spaced apart locations along the bottom wall; means defining a hole extending through each tab, and a locking pin extending through the hole in each tab.
 26. The connector defined in claim 25 wherein said tabs have opposing corners which are beveled.
 27. A connector for a modular surface assembly composed of panels each panel having a double-wall peripheral skirt, said connector comprising a double-ended pin composed of coaxial, mirror-image pin sections having first ends connected together and second ends, each pin section being longer than the total thickness of the double-wall skirt of each panel.
 28. The connector defined in claim 27 wherein said pin is somewhat flexible.
 29. The connector defined in claim 25 wherein said pin has tapered ends.
 30. The connector defined in claim 25 wherein said locking pin has bulbous ends.
 31. the connector defined in claim 27 in combination with a tool comprising an elongated shaft having a tapered end and an opposite end, and an annular member extending laterally from said opposite end. 